Beginning with a histrical survey of the first synthesis (1968) of (+) -twistane reported from our laboratory, developments in the chemistry of high-symmetry chiral cage-shaped compounds are reviewed until our recent successful synthesis (1977) of (+) -D₃-trishomocubane with its absolute configuration determination. Elucidation of their absolute configurations as well as their CD spectra are described, in which emphasis is placed on their structural correlation based on the inherent symmetries.

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The chemistry of silyl diazo compounds is reviewed. Silyl diazo compounds are more stable than the corresponding carbon diazo compounds due to the p_Π-d_Π resonance. Silyl diazo compounds react th a variety of reagents such as electron deficient olefins, nitriles, acids, halogen etc. Silylcarbenes generated by the decomposition of silyl diazo compounds are found to be electrophilic by the reactions with olefins and compounds containing hetero atom. The reactions of silylcarbenes with olefin give stereospecific addition products and with sulfides, ethers, and alkyl halides form the corresponding ylides. The intramolecular reactions of silylcarbenes are also described. It is found that singlet silylcarbenes can produce silaethenes which are species having a silicon-carbon double bond.

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The synthesis of β-sec-alkylnaphthalene by the reaction of naphthalene with 2-butene or propene has been studied by using metal chloride oxide such as AlOCl and TiOCl₂ as catalysts. It has been observed that AlOCl and TiOCl₂ are useful catalysts for the alkylation of naphthalene with 2-butene or propene and also for the isomerization of the alkylation product, and that these catalysts are easily separated from the reaction mixture by filtration or decantation.

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Aldehyde oximes reacted with phosphorous tris (diethylamide) P (NEt₂) ₃ under reflux in THF, giving the corresponding nitriles in good yield. Reaction of benzaldehyde oximes with some trivalent phosphorus compounds was also examined.

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The reaction of various γ-lactones with vinylmagnesium chloride was carried out. From 2, 2, 4-trimethyl-γ-butyrolactone (1), a mixture of 8-hydroxy-6, 6-dimethyl-1-nonen-5-one (2) (yield, 42.5%) and 4, 4-dimethylyl-5-vinyl-6-heptene-2, 5-diol (3) (yield, 18.8%) was obtained. However, in the presence of copper (I) chloride, the yield of (3) was supressed and 8-hydroxy-6, 6-dimethyl-1-nonen-5-one (2) (yield, 42%) was obtained almost exclusively.

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Studies on cathodic-reductive dimerization, co-dimerization, and cyclization are reviewed from a synthetic aspect. The reactions are classified into several types : (1) formation of 1, 2-diols from carbonyl compouds, (2) formation of 1, 2-diamino compounds from imines, (3) dimerization of activated olefins, (4) dimerization of vinyl ketones, (5) co-dimerization between carbonyl compounds and unsaturated compounds. (6) formation of carboxylic acids by addition of carbon dioxide, (7) dimerization and cyclization of halocompounds, (8) formation of carbon-hetero atom bonds and (9) formation of heterohetero atom bonds.

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The manufacture of ε-caprolactam is carried on by means of three processes at present. The first process was developed by IG Farben, at which the first industrial production of ε-caprolactam was begun in 1943. The starting material is phenol, from which cyclohexanone is produced, and then converted to the corresponding oxime. Hydoxylamine is produced by Raschig method. The oxime is transformed into ε-caprolactam by Beckmann rearrangement in oleum. Major amount of ε-caprolactam in the world is manufactured still by this process, which is, however, somewhat modified. The modifications differ with manufacturers. Phenol may be replaced with cyclohexane which is converted to cyclohexanone by air oxidation. Hydroxylamine can be produced also by reduction of either nitrogen monoxide or nitric acid. The second process was developed by Snia Viscosa in 1962. The starting material is toluene, which is converted into cyclohexane carboxylic acid. The treatment of the acid with nitrosyl sulfuric acid in oleum yields ε-caprolactam. The third process was developed by Toyo Rayon (now, Toray) in 1963. The method consists of the photo-reaction of cyclohexane with nitrosyl chloride giving cyclohexanone oxime hydrochloride, which is rearranged in oleum to ε-caprolactam.
The ε-caprolactam manufacture is historically reviewed.

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